MOF-derived NiCo₂S₄ nanoparticles and hollow carbon hybrid spheres compactly concatenated by electrospun carbon fibers have been successfully synthesized and employed as self-standing cathode electrodes for aqueous alkaline Zn batteries.

To improve the interaction between cells and scaffolds, the appropriate surface chemical property is very important for tissue engineering scaffolds. In this study, the thermoplastic polyurethane (TPU) nanofibers was firstly fabricated by electrospinning technique, and then its surface was modified with cellulose nanofibrils (CNF) particles by ultrasonic-assisted to obtain TPU/CNF nanofibers. Subsequently, the TPU/CNF-polydopamine (PDA) composite nanofibers with core/shell structure were fabricated by PDA coating method. In comparison with TPU nanofibers, the uniformization of PDA coating layer on the surface of TPU/CNF composite nanofibers significantly increased due to the addition of CNF, which used as the active sites to guide the PDA particles accumulated along with the fiber direction. The water absorption and hydrophilicity of TPU/CNF-PDA composite nanofibers were significantly increased in comparison with those of TPU and TPU/CNF nanofibers. The mechanical properties of the TPU/CNF-PDA composite nanofibers were higher than those of the TPU and TPU/CNF nanofibers due to the formation of strong hydrogen bonds between PDA and TPU/CNF, making TPU, CNF and PDA strongly adhere to each other. The attachment and viability of mouse embryonic osteoblasts cells (MC3T3-E1) cultured on TPU/CNF-PDA composite nanofibers were obviously enhanced compared with TPU and TPU/CNF nanofibers. Those results suggested that the modified TPU/CNF-PDA composite nanofibers have excellent mechanical and biological properties, which promoting them potentially useful for tissue engineering scaffolds. The presented strategy represents a general route to modify the surface of scaffolds, which are promising for tissue engineering applications.

As an essentially multi-input multi-output process, determination of optimal conditions for laser cladding normally requires multi-objective optimization. To understand multi-response coupling, the effects of processing parameters on the morphology quality of multi-pass laser claddings of Fe50/TiC on medium carbon steel AISI 1045 were investigated based on composite central design using response surface methodology. Multiple responses, including clad width, flatness, and non-fusion area, were transformed into a single objective through grey relational analysis, with weights objectively identified by principal component analysis. The correlation between grey relational grade (GRG) and process parameters was established by regression analysis. The results show that the GRG response model has excellent goodness of fit and predictive performance. A validation experiment was conducted at the process condition optimized for maximum GRG. The relative error of the predicted optimal GRG is 4.87% whereas those of interested individual objectives, i.e. clad width, flatness, and non-fusion area, are 5.73%, 2.97%, and 6.73%, respectively, which verifies the accuracy of the established model. The investigation of mechanical properties suggests the hardness of substrate can be improved from 20 HRC to 60 HRC and wear resistance to over 8.14 times better.